Report Number 1: Metallurgical characterization of the HAZ in A516-70 and evaluation of fracture toughness specimens
An extensive study has been conducted on A516 grade 70 steel to investigate the effect of shallow cracks in weldment HAZs. Charpy V-notch (CVN) and crack-tip opening displacement (CTOD) tests were utilized to characterize the fracture toughness behavior of the heat-affected zone (HAZ) of A516-70 SMAW weldments. The test results are explained on the basis of microstructural features in the HAZ and fractographic examination. Optical light microscopy (OLM) and scanning electron microscopy (SEM) were used for these evaluations. A computer-assisted imaging system was also utilized and it proved to be a powerful tool for fracture surface analysis. It was evident from the testing of thermally simulated HAZs of A516-70, that the CGHAZ has the lowest toughness. The need for welding techniques to create actual weld HAZs without an influence from secondary weld passes was addressed during the course of this investigation. A welding procedure was developed which is capable of producing ``singular`` HAZs in actual welds. The ``singular`` HAZ technique produced a non-overlapped continuous HAZ through the full plate thickness. A good correlation was found between thermally simulated HAZ behavior and ``singular`` HAZ behavior in terms of fracture toughness, hardness and microstructure.
- OSTI ID:
- 109997
- Journal Information:
- Bulletin - Welding Research Council, Journal Issue: 403; Other Information: PBD: Jul 1995
- Country of Publication:
- United States
- Language:
- English
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